This topic has been thoroughly dicussed, and it the responses are fascinating. I would not make tangs out of titanium myself as the inspection of the material is not clear to me. My bread and butter customer is a company that makes titanium investment castings, and I have access to all sorts of technical information. Titanium, in order to be machined has to have certain safety precautions as it is to my knowledge highly flammable. So, I refuse to work with it. I machined magnesium once, and had fun with the chips outside my shop. Someone mentioned in this topic that he had it cut with a waterjet. This modern waterjet technology works fine and it is probably ok because the stream of water and abrasive extinguish any flame up, but otherwise tangs are no big deal dimensional tolerance wise. The mounting holes can always be reamed. I understood that the boats that are used for racing use all sorts for gimmicks for reducing weight, with titanium on top of the list. Since Saraband won a Transpac in her class, the go fast crowd takes more risks than a sailor dedicated to safe cruising should.

Regarding the square tang holes for carriage bolts: My speciality is the design and modification of investment casting wax pattern molds, a specialty that I switched from the plastics injection mold industry. I had a decade ago a tooling job for insertable saw teeth for one of the biggest woodproducts companies in the US. Their newly designed saw tooth inserts for saw mills kept breaking and I suggested to their engineering department to eliminate the sharp corner around the shank to the toothbody by making a radiused groove into the toothbody tangent to the shank. Their saw teeth did not break anymore after that. -- The same thing should (!) work with the square holes that are punched in the Westsail tangs. It is a simple operation, use a 1/8" or 5/32" endmill and cut along the longitudal side of the square hole of the tang a half diameter of the end mill into all four corners.  That should take care of the notch effect. In any case, tangs and swedged fittings should be tested for cracks. There are kits available to do a basic dye test. All it shows if there is a crack when the solution soaks in through capillary action, is the discolored line. Another simple freebe die test: Look for rust lines!

Happy and safe sailing,

Mike

P.S The dye flaw detector inspection kits are available in two versions: the Visible around $100 and the Fluorescent around $600-$700. They are available from Mc Master-Carr (562)692-5911; MSCdirect.com, Grainger and others. There are also material testing laboratories. My bread and butter customer has a complete lab at each of their investment foundry plants, so if you know someone in the industry that uses extreme quality control, they may be able to verify your standing rigging. MZ